HAMMOND BAY, Mich. — An invasive species, sea lamprey nearly drained the life out of the Great Lakes, latching onto its lucrative fishery with a suction cup mouth, threatening the livelihoods of the thousands whose careers depended upon their catch.
A new documentary released to streaming services this Friday, THE FISH THIEF: A Great Lakes Mystery tells this story of the sea lamprey's rise and fall on the lakes.
"The reason you have small-town economies and small businesses, jobs in fishing and jobs in tourism around the Great Lakes, is because of science and government," said Director Lindsey Haskin, who was commissioned by the Great Lakes Fishery Commission to make the film.
In the early 20th century, commercial fishermen on the Great Lakes cast their nets as if their catch would never run low. People assumed "there would always be plenty to catch," narrator J.K. Simmons says in the documentary.
Suddenly, fish populations collapsed. Scientists knew overfishing was a problem, but pinpointed sea lamprey as their primary suspect. The eel-like creature had infiltrated the Great Lakes through man-made canals, making the freshwater bodies their permanent home.
"A perfect storm of biological invasion," said Marc Gaden, the executive secretary for the Great Lakes Fishery Commission.
While considered a parasite in its native habitat, the invasive species acted much more like a predator in the Great Lakes. Smaller fish could not survive its toothy grip. In its lifetime, a single lamprey can chew through forty pounds of fish. The fishery faced an existential threat.
"Why was this so devastating? There's nearly unlimited spawning habitat in the Great Lakes for sea lamprey," Gaden said. "These eating, lethal, killing machines moved from fish to fish before moving to the streams to spawn."
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In 1954, a treaty between the United States and Canada formed the Great Lakes Fishery Commission, created in part to control the rising sea lamprey population.
"These commercial fishing industries were hurting," Haskin said. "These businesses were going under."
At a research lab in Hammond Bay, Michigan, a team of scientists looked for a solution to the lamprey problem in chemistry. They needed something that would kill the invasive species and spare all other life-forms.
"It took years and years and years," Haskin said.
The 5,209th chemical tested at the Northern Michigan laboratory — a compound called 3-Trifluoromethyl-4-Nitrophenol (TFM, for short) was the "silver bullet."
"That was the gold standard, the moonshot," Gaden said. "We needed to find something that would make sure that the cure would not be worse than the disease."
Soon enough, the lampricide was applied to streams and rivers across the Great Lakes region, targeting juvenile lamprey as they matured in the cool, shallow waters.
The result? Today, the invasive species' population has been reduced by about 90 percent and the Great Lakes commercial fishery, valued at $7 billion, supports more than 70,000 jobs. TFM brought it back from the brink.
"The whole story of this film is the perseverance, the science that went behind it and the attitude that we can solve this problem," Gaden said. If we didn't, we'd have no fishery of which to speak."
THE FISH THIEF: A Great Lakes Mystery is available in the U.S. and Canada to stream, download, or rent on platforms including Apple TV/iTunes, Amazon, Google/YouTube, and Tubi.
To learn more about the documentary, click here.
